The Best of ObesityWeek 2024
Presidents’ Wrap Up: Highlights from ObesityWeek 2024
By Marc-Andre Cornier, MD, FTOS & Jamy Ard, MD, FTOS
In this closing wrap-up, Drs. Marc-Andre Cornier and Jamy Ard review ObesityWeek’s highlights. The opening plenary advanced a theme of global obesity care, featuring a patient advocate’s story and a discussion on using science to move beyond blame, shame, and stigma toward compassionate, meaningful treatment. Sessions spanned body-weight regulation science, clinical tools, new workshops, and centering patient voices, alongside international collaborations addressing access to care and terminology—favoring terms such as “obesity medications” over potentially more stigmatizing language. Major clinical-trial results and a record exhibit hall featured prominently. Looking ahead, next year will frame obesity as a chronic disease, emphasizing its complications across a dedicated track.
Faculty Interviews
Gain valuable insights from an international panel of experts.
Screening for Obesity
By Donna Ryan, MD, FTOS
Obesity screening should be integrated into routine primary care, with body mass index measured at every office visit as a core electronic health record metric. However, BMI reflects only body size, a function of height and weight, and does not convey a patient’s health status. Assessment should therefore extend to waist circumference, a practical measure of abdominal adiposity, using thresholds of 35 inches in women and 40 inches in men to flag elevated risk. Anthropometric measures should be combined with cardiometabolic evaluation, including blood pressure at every visit, to determine whether obesity is driving cardiovascular risk and to guide targeted risk reduction.
SELECT Trial and CVD Breakthroughs
By Donna Ryan, MD, FTOS
Follow-up analyses from the SELECT trial reinforce semaglutide’s cardiovascular benefit in people with overweight or obesity and established cardiovascular disease but without diabetes, where it reduced major adverse cardiovascular events, heart attack, stroke, and cardiovascular death, by 20%. Mediation analyses suggest this protection is largely independent of the degree of weight loss. Spanning over four years and a large, globally diverse population, benefits proved consistent across BMI categories, regions, and subgroups. Additional findings include reduced heart-failure hospitalization and death, reversion to normoglycemia in roughly two-thirds of participants with prediabetes, and slowed kidney-disease progression, positioning semaglutide as a disease-modifying therapy warranting proactive clinical use.
Integrating Semaglutide in Practice
By Donna Ryan, MD, FTOS
Translating the SELECT trial into practice begins with a clear call to action: clinicians should review patients individually to identify those who mirror the trial population and would benefit most. SELECT participants all had established cardiovascular disease and were already optimally managed, on statins, with controlled blood pressure and antiplatelet therapy, yet retained roughly 20% residual cardiovascular risk. Adding semaglutide addresses this residual risk. Priority candidates include patients with established coronary disease, prior myocardial infarction, or symptomatic peripheral artery disease. For these high-risk individuals, semaglutide should be incorporated for secondary prevention, with evidence supporting reductions in heart attack, stroke, and cardiovascular death.
The Evolving Universe of GLP-1 Medicines
By Daniel J. Drucker, MD
The GLP-1 receptor agonist field is advancing along several fronts likely to reshape treatment within five years. First, new agents extend beyond single GLP-1 receptor agonists to dual, triple, and even quadruple combinations, plus amylin-based approaches, offering greater efficacy and added benefits for liver, kidney, and cardiovascular disease. Second, delivery is diversifying, from daily tablets and weekly injections toward monthly formulations and eventually cell- and gene-based therapies. Third, indications are expanding rapidly, with positive trials in metabolic liver disease, sleep apnea, cardiovascular and kidney disease, and studies underway in addiction and neurodegeneration. Neurodegenerative disease, supported by GLP-1’s established safety record, holds promising potential.
Geroscience and Obesity
By Stephen Kritchevsky, PhD
Age is the dominant risk factor for major chronic diseases, including cancer and heart disease, with risk rising exponentially over the lifespan. Geroscience proposes targeting the biology of aging itself to delay these conditions. Decades of animal research, spanning yeast, worms, flies, mice, and primates, identify caloric restriction as the most robust intervention for extending lifespan and healthspan, activating cellular maintenance and repair pathways. Applied to older adults, obesity treatment through reduced caloric intake may therefore yield benefits beyond cardiometabolic improvement. Chronic caloric excess accelerates accumulation of cellular damage, impairing protein synthesis, folding, and clearance; restricting intake may counteract these aging processes.
SURMOUNT-1: Three-Year Outcomes
By Sean Wharton, MD, FRCPC, PharmD
Three-year (176-week) outcomes from SURMOUNT-1 provide the longest-duration evidence for tirzepatide in obesity, addressing the questions patients most often raise: magnitude, durability, and safety. Substantial weight loss, approximately 20%, achieved in the first year was sustained through nearly four years, without attenuation. The extended safety data revealed no new signals beyond the expected gastrointestinal effects such as nausea and vomiting. Critically, the trial demonstrated marked prevention of progression from prediabetes to type 2 diabetes, with 99% of treated participants remaining free of type 2 diabetes. As a dual GIP/GLP-1 receptor agonist, tirzepatide’s combined mechanism appears to enhance efficacy relative to single-hormone approaches.
SURMOUNT-1: Managing Medication Side Effects
By Sean Wharton, MD, FRCPC, PharmD
The gastrointestinal side effects of incretin-based obesity medications, nausea and early satiety, are an expected, mechanism-based phenomenon: these are gut hormones normally released after eating, so administering them produces an amplified version of the post-meal signal. Patient education and expectation-setting are therefore central, since understanding that symptoms are transient and diminish over time improves tolerance. Effective management strategies include slow, gradual dose titration and remaining longer at lower doses; temporarily pausing or skipping a dose when needed; using anti-nausea medications to control symptoms; and dietary adjustments such as smaller portions, particularly during the early treatment phase when side effects are most pronounced.
Tirzepatide in Obesity and Prediabetes Treatment
By Louis Aronne, MD
Three-to-four-year follow-up of tirzepatide in participants with obesity and prediabetes demonstrated a striking 94% reduction in progression to type 2 diabetes versus placebo, among the most impressive prevention results reported. Tirzepatide and semaglutide, though both incretin-based, differ mechanistically: semaglutide targets the GLP-1 receptor, whereas tirzepatide is a dual GIP/GLP-1 agonist, and combining these actions enhances efficacy. Tirzepatide produces 22–23% weight loss; future triple agonists and GLP-1/amylin combinations promise 25–30%, approaching bariatric surgery outcomes. This signals a shift toward treating obesity proactively to prevent cardiometabolic complications, rather than waiting for those complications to emerge, ushering in a new era of preventive care.
What is “optimal weight loss“?
By Louis Aronne, MD
The advent of highly effective obesity medications has made defining optimal weight loss a meaningful clinical question, previously moot when treatments achieved only modest reductions and goals were 5–10%. Two complementary framings emerge. By percentage, losing at least 15% of body weight resolves most obesity-related complications, though some conditions require 25–30%. Alternatively, a treat-to-target approach analogous to blood pressure, LDL, and HbA1c goals proposes anthropometric targets, a BMI around 27 or below and a waist-to-height ratio near 0.5, where complication risk is minimized without reaching normal BMI. Because mortality rises at low BMI, patients should not fall below 22, sometimes warranting dose reduction.
Brain Gut Microbiome and Obesity
By Arpana Church, PhD
The gut microbiome causally influences obesity, demonstrated when transplanting microbiota from obese animals induced obesity in lean recipients, and is connected to the brain. The brain and gut microbiome form a bidirectional communication loop, with top-down signaling from the brain shaping the microbiome and bottom-up signaling influencing the brain; in obesity, this communication becomes disrupted, driving altered eating behaviors and weight gain. Viewing obesity as a whole-system disorder, encompassing brain, microbiome, genetics, inflammation, behavior, and environment, reveals multiple intervention points. These include brain-directed approaches such as stress reduction, cognitive behavioral therapy, and mindfulness; small dietary additions nourishing beneficial bacteria; and addressing environmental stressors.
Weight and Obesity Perception to Perspective
By Robyn Pashby, PhD
Outdated perceptions, that weight reflects willpower or lifestyle choices alone, are often held by clinicians and patients alike, and unintentionally they undermine clinical care. Patients frequently arrive carrying histories of judgment and shame, believing that trying harder should suffice or that medication is “the easy way out.” Such beliefs erode trust, foster discouragement, withdrawal from care, anxiety, and emotional eating. A trauma-informed perspective recognizes that many patients bear lasting scars from weight stigma. Its principles include establishing safety, using intentional and nonjudgmental language, and measuring success through functioning, energy, and well-being rather than weight alone—addressing the whole person to enable sustainable engagement.
What are Predictors of Obesity?
By Louis Aronne, MD
Although body mass index has long been the standard, easily measured metric enshrined in obesity guidelines, it poorly captures where fat is distributed, a critical determinant of health risk. Waist-to-height ratio, available for years, is emerging as an equal or superior predictor, particularly of cardiovascular disease, which BMI reflects weakly. This distinction matters because excess visceral adiposity confers substantial cardiovascular risk even in individuals whose BMI appears normal. Proposed thresholds classify a waist-to-height ratio of 0.4–0.49 as normal, 0.5–0.59 as increased risk, and 0.6 or above as highest risk. Adopting this measure identifies at-risk normal-weight patients previously missed, enabling appropriate treatment.
Long-term Effects of Semaglutide
By Donna Ryan, MD, FTOS
The SELECT trial provided several additional years of long-term observation in a large, diverse population of roughly 17,600 patients, yielding one of the most robust datasets available on the extended safety and efficacy of semaglutide. Reassuringly, these long-term findings reinforce existing clinical understanding of the GLP-1 receptor agonist class without revealing new safety concerns or unexpected red flags. They confirm established knowledge of how to use these medications safely, their tolerability profiles, and strategies for managing common gastrointestinal effects such as nausea and vomiting. Collectively, this powerful, large-scale evidence strengthens clinician confidence in the sustained, long-term use of this drug class.
SELECT CVD Outcomes and Obesity
By Donna Ryan, MD, FTOS
The SELECT trial marked a milestone by demonstrating that semaglutide reduces major adverse cardiovascular events, including heart attack and stroke, in high-risk patients with overweight or obesity and established cardiovascular disease but without diabetes. These findings are reshaping practice and policy: Medicare, which had long resisted covering obesity medications, now reimburses semaglutide for secondary cardiovascular prevention, with Medicaid frequently following. The benefits appear to extend beyond cardiovascular events to heart failure and chronic kidney disease, supporting potential broadening of indications. Emerging analyses also reveal a striking anti-inflammatory effect within the trial population, suggesting inflammation reduction as an important mechanism underlying these outcomes.
